CO2 currently at highest level in 2.1 million years

About | Contact | Mongabay on Facebook | Mongabay on Twitter | Free newsletter

SHARE:

CO2 currently at highest level in 2.1 million years
mongabay.com
June 18, 2009

Atmospheric carbon dioxide levels are higher than any point in the last 2.1 million years, report researchers writing in the journal Science.

Analyzing the shells of single-celled plankton buried under the Atlantic Ocean off the coast of Africa, Bärbel Hönisch, a geochemist at Columbia University's Lamont-Doherty Earth Observatory, and her colleagues dtermined that peak CO2 levels over the last 2.1 million years averaged only 280 parts per million. By comparison current CO2 levels stand at 385 parts per million, or 38% higher than the long-term peak.

Annual mean atmospheric CO2 concentrations (ppm), 1850-2008 [top]; Monthly atmospheric CO2 records from sites in the SIO air sampling network 2005-June 2009 [bottom].

The findings provide new insight on the role of CO2 in global cycles of cooling and warming, suggesting that a shift towards longer glacial cycles — producing a major ice age about every 100,000 years instead of every 40,000 — some 1.2 million to 500,000 years ago was the result not of declining CO2 levels, but another factor, perhaps Earth's orbit and tilt, which determines how much sunlight falls on each hemisphere, or changes in how previous ice ages affected subsequent ice ages.

"Previous studies indicated that CO2 did not change much over the past 20 million years, but the resolution wasn't high enough to be definitive," said Hönisch. "This study tells us that CO2 was not the main trigger, though our data continues to suggest that greenhouse gases and global climate are intimately linked."

B. Hönisch et al. Atmospheric Carbon Dioxide Concentration Across the Mid-Pleistocene Transition. SCIENCE VOL 324 19 JUNE 2009

CITATION:
mongabay.com (June 18, 2009). CO2 currently at highest level in 2.1 million years. http://news.mongabay.com/2009/0618-co2.html

Tags:
carbon dioxide climate change earth science environment green

print

Environmental news index | RSS | News Feed | Twitter | Home

Advertisements:

Mongabay Store
Wildlife of Madagascar T-shirt		Bold and Dangerous - Pygmy tyrant
Love me before I'm gone - Gladiator frog		Licking this frog may make you crazy

DON'T LIKE ADS? Become a mongabay supporter

WEEKLY NEWSLETTER

RECENT FEATURES

		As Amazon deforestation falls, food production rises
		Biggest environmental news stories of 2011
		The year in review for rainforests
		Our top nature pictures of 2011

Photos

Brazil	China	Colombia
Costa Rica	Deforestation	Gabon
India	Indonesia	Kenya
Madagascar	Peru	Rainforest

ABOUT
Mongabay.com seeks to raise interest in and appreciation of wild lands and wildlife, while examining the impact of emerging trends in climate, technology, economics, and finance on conservation and development (more)

Help support mongabay.com when you buy from Amazon.com

CALENDARS

BOOKS BY MONGABAY AUTHORS

Conservation in an age of mass extinction

FREE WEEKLY NEWSLETTER

HIGH RESOLUTION PHOTOS / PRINTS

Copyright mongabay 2010

Carbon dioxide (CO2) emissions generated from mongabay.com operations (server, data transfer, travel) are mitigated through an association with Anthrotect,
an organization working with Afro-indigenous and Embera communities to protect forests in Colombia's Darien region.
Anthrotect is protecting the habitat of mongabay's mascot: the scale-crested pygmy tyrant.